Child resistant safety closures comprising two nested closure members are well known in the art. Typically, the outer and inner closure members are provided with cooperating sets of lugs which engage each other when the outer closure is rotated in the direction to apply the closure. When the outer closure member is rotated for removal, these lugs cam or ratchet past each other on inclinded surfaces, so that the closure member may not be removed by mere rotation. To provide positive engagement of the inner and outer closure member for removal, the prior art has employed additional sets of cooperating lugs or projections, which are normally held completely separated by some flexible means. To remove these closures, the outer closure member must be variously squeezed, pushed, or otherwise manipulated, to overcome the flexible separating means, and bring the removing lugs into positive engagement.
The prior art devices thus employ different sets of cooperating lugs to apply and remove the closure. In many prior art devices if the separating means is damaged by abuse, storage with a top load, or simply by repeated use, the outer closure will fall into positive engagement with the inner closure thereby eliminating the safety feature. Typical closures of this type are set forth in U.S. Pat. Nos. 3,776,407, 3,946,890, 4,480,759, and British Patent Specification No. 152,999.
Such closures function well in normal usage. However, when a heat shrunk tamper indicating band is applied to the package and the band is shrunk, there is a tendency for the outer closure member or shell to be drawn axially into engagement with the inner closure member or shell.
Accordingly, among the objectives of the present invention are to provide a child resistant closure which obviates and precludes any tendency of the closure members to be in engagement when a tamper indicating band is utilized therewith.
In accordance with the invention, one or more integral resilient wings are provided on the inner surface of the base wall of the outer member or the inner surface of the base wall of the inner member such that the outer member is normally held out of engagement with respect to the inner member and will not be brought into engagement by the shrinkage of a tamper indicating band thereon.